Patients, such as the elderly or infirm, are often required to spend long periods of time in a chair, such as a reclining chair or a wheelchair. Because these patients are less mobile, they may not be able to easily sit at a table in a standard chair. Consequently, the patients must perform all tasks, such as eating or reading a book, on their lap.
Tray tables have been developed that attach directly to invalid chairs. Some such tables have runners that can be inserted into cavities in brackets that are fixedly mounted to the arms of the chair. These tables are useful because they permit easy mounting of a tray table to a chair. Further, the patient can remove the tray himself by merely pushing the tray forward. However, because the tray tables are not fixed, the runners can slip out of the brackets accidentally such that the tray table falls onto the patient, or completely off of the chair onto the floor.
Tray tables have also been developed that lock the runners to the brackets. Typical locking devices include detents on the brackets that engage holes in the runners. The locking devices are not always accessible to the patient and are often too stiff for a patient to disengage. Consequently, patients become imprisoned in the chairs behind locked tray tables.
It is therefore an object of the present invention to provide a tray table for an invalid chair which can be operated in a locking mode where a locking mechanism engages the runners of the tray or in a sliding mode, where locking mechanism does not engage the runners of the tray.
It is another object of the present invention to provide a caregiver a means for Selecting the operating mode of a detent. In a locking mode, the selecting means allows a detent mounted on a bracket to engage a runner attached to a tray table, thus locking the tray table in position. In a sliding mode, the selecting means prevents the detent from engaging the runner. Thus, the runners of the tray table are free to slide in the brackets.
It is also an object of the present invention to provide a method of operating a tray table such that the table can be used in a sliding mode where a locking mechanism does not engage the runners of the tray and the table can be used in a locking mode where the locking mechanism does engage the runners of the tray.
It is also an object of the present invention to provide a method of making a retainer, such as a bracket, for a tray table capable of operating in a sliding mode and a locking mode.
These and other objects of the present invention will be clear from the following description of the invention.